Planted tsnk noobie needing CO2 advice

Hi Ron,


I'm in the setup stages and just went through much investigation on CO2. I have a 150g and bought 2 of the CarbonDoser units (you will definitely need more than one). I think they are great. I use a pH probe in the tank for constant measurement and get CO2 value from chart. I can get the pH down to where I need in about 90 minutes. Room for improvement I think. Still trying to figure out the best way to keep it at the proper level... I've also used drop checkers. The downside to them is they lag by a couple of hours.


Ken

 

Use a pH probe to monitor pH drop. Drop checkers are very slow-reacting, and depending on placement and tank lighting, the drop checker can be hard to see the color well.


As far as I know, there's no specifically marketed diffuser/reactor suitable for larger tanks -- check the many threads here about Cerges reactors, made from home water filter housings.

 

I have a regulator from Green Leaf Aquariums (they get a thumbs up too) and it has a separate bubble counter for each reactor. I'm going to try to upload a pic.. You can add as many 'blocks' as you have places to run CO2, pretty cool as each has it's own bubble counter and needle valve (white knob under bubble counter).




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Try custom CO2 regulators. You pay less but better quality.

 

Don't waste your money on the MixMax. DIY PVC pipe reactor is cheaper and more effective.

 

I don't recommend the CarbonDoser, either. The location of the pump creates a vacuum which creates negative chamber pressure. You need positive pressure or the gas goes undissolved and a gas pocket quickly forms. It is pressure that diffuses CO2 (and other gasses) into the water, not contact time.

 

These are the minimum items needed to create a PVC reactor without inlet for CO2:


2" x 3/4" PVC bushing (spigot x fNPT)


2" x 12" PVC pipe


2" x 2" x 3/4" PVC threaded tee (socket x socket x fNPT)


2" PVC plug


5/8" barb x 3/4" mNPT tube fitting adapter (qty=2)


Use the barb size of your tubing. PVC diameter and length can be larger; fittings must match.

 

Parts mistake. The 2" x 3/4" PVC bushing is supposed to be a 2" slip x 3/4" threaded reducer coupling.

 

Here is a 2" Barr CO2 reactor design that is currently in use. Made this unit 6+ years ago. Reactor is driven by Eheim 2213 on 20L.





CO2 in(top of pic) Air bleed(bottom of pic)





Here is the same unit HOB used years ago


You will have to scale up for your size tank. The design is the same.

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Unless you have a 1000 gallon tank, 4" is excessively large and expensive. 3" is max for most tanks.. The purpose of the larger inner diameter is to slow the water velocity. Too narrow and the flow remains high which causes gas to be carried out with the flow.

 

The Cerges reactors are around 4" diameter?